Computational Study of Flow Characteristics of an Inducer Dropleg Configuration for Pulp Pumping Applications

The present work numerically investigates the flow characteristics and performance of a dropleg-inducer configuration for medium consistency (MC) pulp pumping applications. The study employed a commercial CFD solver package to carry out the steady-state single-phase Newtonian fluid (water) simulations using RANS-based k-ε turbulence model. Three different normalized axial spacing of the inducer from the dropleg exit (L/D = 0.75, 1.15 & 1.5) were studied for three normalized rotational speeds (Ṅ = 0.6, 1 & 1.2) considering both design and off-design operating conditions. The results are discussed in the context of velocity streamlines at different planes, contours of velocity and turbulence intensity, and plots of performance parameters such as power consumed, and power number thereby allowing for an assessment of the inducer’s performance with changing distances from the dropleg and different rotational speeds considering the operational range of the MC pump. The findings reveal that change in the axial spacing and rotational speeds significantly impacts the flow pattern within the dropleg and the inducer passage. Consequently, these changes affect the turbulence characteristics and the power consumption by the inducer, which will in turn affect the overall performance of the MC pump.